California Lawmakers Take Step Forward on Bill to Simplify ADU Development

California homeowners looking to build accessory dwelling units (ADUs) moved closer to simplified regulations this week as Assembly Bill 1154 passed unanimously out of the Assembly Local Government Committee.

The legislation, authored by Assemblymember Juan Carrillo, aims to create unified rules for small ADUs by eliminating what housing advocates describe as contradictory regulations that have complicated the development process.

ADUs are secondary housing units built on single-family residential properties, such as converted garages, basement apartments, or small backyard structures.

They allow homeowners to generate rental income, house family members, or create additional housing in existing neighborhoods.

Currently, California law treats ADUs and Junior ADUs (JADUs) as separate categories with different permitting requirements, fees, and occupancy rules, leading to project delays and increased costs for homeowners.

The proposed changes come as California continues addressing its housing shortage through increased ADU construction.

More than 85,000 ADU units were approved statewide between 2016 and 2022, making these units an increasingly important tool for adding affordable housing options.

Housing advocates argue that streamlining the regulatory framework will make it faster and more cost-effective for property owners to contribute to the state's housing supply, particularly benefiting low- and moderate-income homeowners who view ADUs as opportunities to build wealth or accommodate multigenerational families.